An aluminum-containing thin film material exhibits specific electric and optical characteristics and has found wide applications. For example, an aluminum or aluminum alloy thin film has been used as an LSI wiring material for its high conductivity and electromigration resistance. An aluminum oxide based thin film has been used as a hardcoat of machine parts and tools; an insulator film, a gate insulator, and a dielectric film of semiconductor memories; electronic components, such as a hard disk MR head; and optical glass for optical communication circuits.
Processes for forming the above-described thin film include sputtering, ion plating, MOD techniques such as a dipping-pyrolysis process and a sol-gel process, and chemical vapor deposition techniques. Chemical vapor deposition techniques (hereinafter abbreviated as CVD) including atomic layer deposition (ALD) is the most suitable for many advantages, such as compositional controllability, excellent step coverage, suitability to large volume production, and capability of hybrid integration.
Various aluminum compounds are known as raw materials for CVD. For example, Patent Literature 1 below discloses trimethylaluminum and alkoxyalanes typified by a dimethylaluminum alkoxide compound as thin film forming materials but gives no mention of the aluminum compound of the invention. Patent Literature 1 reports that AlMe2(OiPr) is the most preferred thin film forming material out of the alkoxyalanes. However, AlMe2(OiPr) is not satisfactory as a material for chemical vapor deposition on account of its low thermal stability. Trimethylaluminum is not satisfactory either as a material for chemical vapor deposition because of its pyrophoricity. Non-patent Literature 1 below discloses an aluminum amide compound of formula (Me2NCH2CH2NMe)Al(NMe2)2 but has no mention of the aluminum compound of the invention.